Office chair



FIG. 1 is a perspective view of an office chair showing our new design, the broken lines are for environmental purposes only and form no part of the claimed design;

FIG. 2 is a right side elevational view of an office chair, the left side being a mirror image, showing our new design;

FIG. 3 is a front perspective view thereof;

FIG. 4 is a top perspective view thereof;

FIG. 5 is a rear perspective view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for an office chair, as shown and described. 